Officers responded to a call to check on the welfare of 54-year-old Bruce Boyd at his Wurz Street home.
His wife let officers into the home and they encountered the man holding a knife and two apparent self-inflicted wounds, police said.
The officers backed out of the home as Boyd followed, still holding the knife. The officers ordered him to drop the knife.
Police said he charged at officers and at least one officer fired his weapon, striking Boyd.
He was pronounced dead at South Shore University Hospital in Bay Shore.
The man had no previous arrests or domestic violence incidents, but police said they had a previous history of emotional and medical issues.
Police said the man was a retired New York City correction officer.
The man's wife is safe.
No officers were injured in the incident.
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